Oxygen anion-releasable purple clay material and preparation method of purple clay

Abstract

This invention discloses a purple clay pottery material capable of releasing negative oxygen ions and a method for preparing purple clay pottery, belonging to the technical field of purple clay pottery materials. The raw materials are as follows (in parts by weight): 55-75 parts synthetic purple clay, 8-18 parts surface-modified tourmaline powder, 5-12 parts core-shell structured nano-negative ion powder, 12-22 parts metakaolin, 6-12 parts porous quartz sand, 8-14 parts potassium feldspar, and 2-4 parts crystal-controllable rare earth composite oxides. This invention, employing the above-mentioned method for preparing a purple clay pottery material capable of releasing negative oxygen ions, overcomes the technical bottlenecks of traditional purple clay pottery's reliance on natural mineral clay and poor functional stability through the synergistic effect of raw material innovation, modification processes, and refined preparation. It achieves multiple breakthroughs in negative ion release efficiency, structural performance, and industrial adaptability.

Description

Technical Field

[0001] This invention relates to the field of Zisha pottery materials technology, and in particular to a Zisha pottery material that can release oxygen negative ions and a method for preparing Zisha pottery. Background Technology

[0002] Zisha pottery, a traditional ceramic material that combines practicality and artistry, primarily relies on natural Zisha clay, whose main components are silicon dioxide, alumina, iron oxide, and clay minerals. In recent years, with the increasing demand for functional ceramic materials, introducing mineral additives with negative ion-releasing capabilities into Zisha pottery has become a research hotspot, aiming to endow it with additional functions such as air purification and improvement of the microenvironment.

[0003] However, natural purple clay is limited by regional mineral resources, resulting in significant fluctuations in composition. Furthermore, the content of residual organic matter and impurities in natural clay minerals is unstable, making it difficult to precisely control sintering performance during the green body preparation process, leading to poor consistency in finished product quality. Traditional methods directly add mineral powders such as tourmaline powder and negative ion powder, but due to differences in mineral surface polarity, they have poor compatibility with the purple clay matrix, easily forming agglomerates and reducing negative ion release efficiency. Moreover, without surface modification or structural design of the additives, component segregation or coating peeling easily occurs during high-temperature sintering, resulting in insufficient sustained negative ion release. Current methods simply involve grinding raw materials in a conventional ball mill, resulting in uneven particle size distribution and affecting the density of the green body. The aging process uses a single temperature and humidity condition, which cannot fully promote the hydration reaction of clay minerals and the decomposition of organic matter, leading to insufficient plasticity of the green body. The firing process lacks segmented control of atmosphere and heating rate, making it difficult to achieve crystal form regulation of rare earth composite oxides and the stable existence of the negative ion functional phase, resulting in large fluctuations in the negative ion release of the final product. Summary of the Invention

[0004] The purpose of this invention is to provide a purple clay pottery material that can release oxygen negative ions and a method for preparing purple clay pottery, so as to solve the above-mentioned problems.

[0005] To achieve the above objectives, the present invention provides a purple clay pottery material that can release oxygen negative ions, comprising the following raw materials in parts by weight: 55-75 parts synthetic purple clay, 8-18 parts surface-modified tourmaline powder, 5-12 parts core-shell structured nano negative ion powder, 12-22 parts metakaolin, 6-12 parts porous quartz sand, 8-14 parts potassium feldspar, and 2-4 parts crystallization controllable rare earth composite oxide.

[0006] The synthetic purple clay comprises: 40-60 parts montmorillonite, 20-30 parts kaolinite, 10-20 parts illite, 10-15 parts quartz sand, 5-10 parts hematite powder, and 3-8 parts alumina powder.

[0007] The surface-modified tourmaline powder is tourmaline micro powder modified by silane coupling agent KH-550;

[0008] The core-shell structured nano-negative ion powder uses tourmaline nanoparticles as the core and is coated with a titanium dioxide-zinc oxide composite coating on the outside. The average particle size of the core-shell particles is 80-150 nm.

[0009] The crystal-controllable rare earth composite oxide is Ce with a fluorite-type crystal structure. 0.8 La 0.2 O 1.9 Its specific surface area is 20-35m². 2 g.

[0010] Preferably, in the above-mentioned purple clay ceramic material that can release oxygen negative ions, the porous quartz sand has a pore size distribution of 1-5μm and a porosity of 20%-30%, and its surface is loaded with nano-silver particles accounting for 1%-3% of the weight of the quartz sand.

[0011] A method for preparing purple clay pottery using purple clay material that releases negative oxygen ions, as described above, includes the following steps:

[0012] S1. Raw material pretreatment: Tourmaline powder and silane coupling agent KH-550 are mixed at a mass ratio of 10:1-15:1, ultrasonically treated at 60-80℃ for 30-50 minutes, and dried to obtain surface-modified tourmaline powder; nano-negative ion powder is mixed with tetrabutyl titanate and zinc acetate solution, and a 5-10nm thick titanium dioxide-zinc oxide composite coating is formed on its surface by sol-gel method to obtain core-shell structured nano-negative ion powder; synthetic purple clay is prepared.

[0013] S2. Composite Mixture: Synthetic purple clay, surface-modified tourmaline powder, core-shell structured nano-negative ion powder, metakaolin, porous quartz sand, potassium feldspar, and crystallization-controllable rare earth composite oxides are fed into a planetary ball mill, using Zirconia balls as the grinding media, with a ball-to-material ratio of 3:1-5:1, at 200-300 rpm. Grind and mix for 1.5-2.5 hours under low temperature and humidity conditions to obtain a uniform powder.

[0014] S3. Plasticizing treatment: Add 25%-30% deionized water by weight of the powder to the powder, and add 0.3%-0.8% sodium carboxymethyl cellulose by weight of the powder as a plasticizer. Use a vacuum ply mill to ply the powder 2-3 times under a vacuum of -0.08MPa to obtain a plastic blank.

[0015] S4. Gradient aging: Place the billet in a variable temperature aging chamber and age it for 12-18 hours at 25℃ and 75% humidity, then raise the temperature to 35℃ and 65% humidity and continue aging for 12-24 hours.

[0016] S5. Microwave-assisted drying: Place the shaped ceramic blanks into a microwave drying oven and dry them in stages at a power of 300-500W. Dry them at 50-60℃ for 4-6 hours, and then raise the temperature to 70-80℃ for 6-8 hours to reduce the moisture content of the ceramic blanks to 5%-8%.

[0017] S6. Segmented firing: Place the dried ceramic blanks into the kiln and fire at 3-5℃. Heat to 600℃ at a rate of 1 minute, hold for 1 hour to remove organic matter; continue heating at 5-8℃. Heating to 1000℃ at a rate of minutes, while introducing a protective atmosphere containing 5%-10% oxygen; finally, heating at 8-10℃... Heat to 1180-1220℃ at a rate of minutes, hold for 3-4 hours, and then cool to room temperature with the furnace.

[0018] Preferably, in the above-mentioned method for preparing purple clay pottery using purple clay material that can release oxygen negative ions, the preparation step of synthesizing purple clay in step S1 specifically includes:

[0019] S01. Preparation of basic raw materials for purple clay: Weigh out 40-60 parts by weight of montmorillonite, 20-30 parts by weight of kaolinite, and 10-20 parts by weight of illite as the main minerals; add 10-15 parts by weight of quartz sand, 5-10 parts by weight of hematite powder, and 3-8 parts by weight of alumina powder as auxiliary components. Put the mixture into a planetary ball mill, using deionized water as the medium, and mill at 300-400 rpm. Grind for 3-5 hours at a constant temperature for 1 minute to obtain a mixed slurry with an average particle size ≤10μm;

[0020] S02, High-temperature calcination crystallization treatment: The mixed slurry is dried at 105℃ until the moisture content is ≤5%, crushed, placed in a sagger, and put into a high-temperature kiln at 10-15℃. Heat to 1000-1200℃ within minutes, hold for 2-3 hours to allow montmorillonite to delaminate, illite to decompose, and mullite crystal nuclei to form. During calcination, introduce a flow rate of 5-10 L / min. Nitrogen protection at 0 min prevents excessive oxidation of iron;

[0021] S03. Fine screening and grading: After the calcined product is coarsely crushed by a jaw crusher, it is passed through a 200-mesh sieve to remove coarse particles, and then classified by an air classifier to make the proportion of particles with a diameter ≤50μm ≥80%, thus obtaining synthetic purple clay.

[0022] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the grinding media of the planetary ball mill in step S2 contains 10%-20% agate balls with a diameter of 1-3mm.

[0023] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the humidity control accuracy of the variable temperature aging chamber in step S4 is ±5%, and the temperature control accuracy is ±2℃.

[0024] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the introduction rate of the protective atmosphere in step S6 is 0.5-1.0 m / s. 3 h, the pressure inside the kiln is maintained at 10-20Pa positive pressure.

[0025] Therefore, by employing the aforementioned method for preparing purple clay pottery that releases negative oxygen ions, the present invention achieves the following beneficial effects:

[0026] (1) Synthetic purple clay is prepared by using common clay minerals such as montmorillonite, kaolinite, and illite as base materials, compounded with quartz sand, hematite powder, and alumina powder, and then processed through a three-step method of grinding, calcination, and sieving. This eliminates the regional dependence and compositional fluctuations of natural clay, and improves the sintering shrinkage rate of the green body through artificial regulation, providing a uniform matrix for the stable dispersion of functional components.

[0027] (2) The surface-modified tourmaline powder is treated with silane coupling agent KH-550, which significantly improves its compatibility with the purple clay matrix and increases its dispersibility by more than 30%, thus avoiding functional failure caused by agglomeration. The core-shell structure nano negative ion powder uses tourmaline nanoparticles as the core and is coated with a 5-10nm thick titanium dioxide-zinc oxide composite coating. The average particle size of the core and shell particles is 80-150nm. During the sintering process, a stable "core-shell" interface structure is formed, which improves the high temperature resistance.

[0028] (3) Gradient aging and microwave-assisted drying: Variable temperature aging promotes full hydration of clay minerals and decomposition of organic matter, and improves the plasticity of the green body; microwave drying raises the temperature evenly to avoid cracking, and the moisture content is controlled with an accuracy of ±2%, providing a stable green body for subsequent molding.

[0029] Segmented firing and atmosphere control: 600℃ heat treatment removes organic matter and avoids residual carbides affecting the crystal form; 1000℃ is filled with a 5%-10% oxygen protective atmosphere to control the rare earth composite oxides to maintain the fluorite crystal structure and promote electron transport and negative ion generation; high-temperature section (1180-1220℃) is precisely temperature controlled to form an interlocking structure between the porous quartz sand and the matrix, improving the compressive strength of the product and achieving the continuity and stability of negative ion release.

[0030] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0031] To better understand the above technical solutions, a detailed description of the specific implementation methods will be provided below. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0033] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0034] This invention provides a purple clay pottery material that can release oxygen negative ions, comprising the following raw materials in parts by weight: 55-75 parts synthetic purple clay, 8-18 parts surface-modified tourmaline powder, 5-12 parts core-shell structured nano negative ion powder, 12-22 parts metakaolin, 6-12 parts porous quartz sand, 8-14 parts potassium feldspar, and 2-4 parts crystallization controllable rare earth composite oxide.

[0035] The synthetic purple clay comprises: 40-60 parts montmorillonite, 20-30 parts kaolinite, 10-20 parts illite, 10-15 parts quartz sand, 5-10 parts hematite powder, and 3-8 parts alumina powder.

[0036] The surface-modified tourmaline powder is tourmaline micro powder modified by silane coupling agent KH-550;

[0037] The core-shell structured nano-negative ion powder uses tourmaline nanoparticles as the core and is coated with a titanium dioxide-zinc oxide composite coating on the outside. The average particle size of the core-shell particles is 80-150 nm.

[0038] The crystal-controllable rare earth composite oxide is Ce with a fluorite-type crystal structure. 0.8 La 0.2 O 1.9 Its specific surface area is 20-35m². 2 g.

[0039] Preferably, in the above-mentioned purple clay ceramic material that can release oxygen negative ions, the porous quartz sand has a pore size distribution of 1-5μm and a porosity of 20%-30%, and its surface is loaded with nano-silver particles accounting for 1%-3% of the weight of the quartz sand.

[0040] A method for preparing purple clay pottery using purple clay material that releases negative oxygen ions, as described above, includes the following steps:

[0041] S1. Raw material pretreatment: Tourmaline powder and silane coupling agent KH-550 are mixed at a mass ratio of 10:1-15:1, ultrasonically treated at 60-80℃ for 30-50 minutes, and dried to obtain surface-modified tourmaline powder; nano-negative ion powder is mixed with tetrabutyl titanate and zinc acetate solution, and a 5-10nm thick titanium dioxide-zinc oxide composite coating is formed on its surface by sol-gel method to obtain core-shell structured nano-negative ion powder; synthetic purple clay is prepared.

[0042] S2. Composite Mixture: Synthetic purple clay, surface-modified tourmaline powder, core-shell structured nano-negative ion powder, metakaolin, porous quartz sand, potassium feldspar, and crystallization-controllable rare earth composite oxides are fed into a planetary ball mill, using Zirconia balls as the grinding media, with a ball-to-material ratio of 3:1-5:1, at 200-300 rpm. Grind and mix for 1.5-2.5 hours under low temperature and humidity conditions to obtain a uniform powder.

[0043] S3. Plasticizing treatment: Add 25%-30% deionized water by weight of the powder to the powder, and add 0.3%-0.8% sodium carboxymethyl cellulose by weight of the powder as a plasticizer. Use a vacuum ply mill to ply the powder 2-3 times under a vacuum of -0.08MPa to obtain a plastic blank.

[0044] S4. Gradient aging: Place the billet in a variable temperature aging chamber and age it for 12-18 hours at 25℃ and 75% humidity, then raise the temperature to 35℃ and 65% humidity and continue aging for 12-24 hours.

[0045] S5. Microwave-assisted drying: Place the shaped ceramic blanks into a microwave drying oven and dry them in stages at a power of 300-500W. Dry them at 50-60℃ for 4-6 hours, and then raise the temperature to 70-80℃ for 6-8 hours to reduce the moisture content of the ceramic blanks to 5%-8%.

[0046] S6. Segmented firing: Place the dried ceramic blanks into the kiln and fire at 3-5℃. Heat to 600℃ at a rate of 1 minute, hold for 1 hour to remove organic matter; continue heating at 5-8℃. Heating to 1000℃ at a rate of minutes, while introducing a protective atmosphere containing 5%-10% oxygen; finally, heating at 8-10℃... Heat to 1180-1220℃ at a rate of minutes, hold for 3-4 hours, and then cool to room temperature with the furnace.

[0047] Preferably, in the above-mentioned method for preparing purple clay pottery using purple clay material that can release oxygen negative ions, the preparation step of synthesizing purple clay in step S1 specifically includes:

[0048] S01. Preparation of basic raw materials for purple clay: Weigh out 40-60 parts by weight of montmorillonite, 20-30 parts by weight of kaolinite, and 10-20 parts by weight of illite as the main minerals; add 10-15 parts by weight of quartz sand, 5-10 parts by weight of hematite powder, and 3-8 parts by weight of alumina powder as auxiliary components. Put the mixture into a planetary ball mill, using deionized water as the medium, and mill at 300-400 rpm. Grind for 3-5 hours at a constant temperature for 1 minute to obtain a mixed slurry with an average particle size ≤10μm;

[0049] S02, High-temperature calcination crystallization treatment: The mixed slurry is dried at 105℃ until the moisture content is ≤5%, crushed, placed in a sagger, and put into a high-temperature kiln at 10-15℃. Heat to 1000-1200℃ within minutes, hold for 2-3 hours to allow montmorillonite to delaminate, illite to decompose, and mullite crystal nuclei to form. During calcination, introduce a flow rate of 5-10 L / min. Nitrogen protection at 0 min prevents excessive oxidation of iron;

[0050] S03. Fine screening and grading: After the calcined product is coarsely crushed by a jaw crusher, it is passed through a 200-mesh sieve to remove coarse particles, and then classified by an air classifier to make the proportion of particles with a diameter ≤50μm ≥80%, thus obtaining synthetic purple clay.

[0051] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the grinding media of the planetary ball mill in step S2 contains 10%-20% agate balls with a diameter of 1-3mm.

[0052] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the humidity control accuracy of the variable temperature aging chamber in step S4 is ±5%, and the temperature control accuracy is ±2℃.

[0053] Preferably, in the above-mentioned method for preparing purple clay pottery from purple clay material that can release oxygen negative ions, the introduction rate of the protective atmosphere in step S6 is 0.5-1.0 m / s. 3 h, the pressure inside the kiln is maintained at 10-20Pa positive pressure.

[0054] To more clearly and in detail introduce the purple clay pottery material that can release oxygen negative ions and the preparation method of purple clay pottery provided by the embodiments of the present invention, the following description will be based on specific embodiments.

[0055] Example 1

[0056] Raw material preparation: Synthetic purple clay was prepared by weighing 50 parts by weight of montmorillonite, 25 parts by weight of kaolinite, 15 parts by weight of illite, 12 parts by weight of quartz sand, 8 parts by weight of hematite powder, and 5 parts by weight of alumina powder. The mixture was fed into a planetary ball mill and ground for 4 hours at 350 rpm using deionized water as the medium (material-to-water ratio 1:0.5) to obtain a mixed slurry with an average particle size of 8 μm. The mixed slurry was dried at 105℃ and then placed in a crucible at 12℃. Heat to 1100℃ in minutes, hold for 2.5 hours, and introduce a flow rate of 8L. After being protected by nitrogen for min and cooled, the material is coarsely crushed by a jaw crusher, screened by a 200-mesh sieve, and classified by an air classifier to produce synthetic purple clay with a particle size ≤50μm of 85% and a chemical composition of SiO2 62%, Al2O3 20%, and Fe2O3 9.5%.

[0057] Surface-modified tourmaline powder was prepared by mixing tourmaline powder with silane coupling agent KH-550 at a mass ratio of 12:1, ultrasonically treating the mixture at 70°C for 40 minutes, and drying it to obtain modified tourmaline powder with a surface grafting rate of 5%.

[0058] Core-shell structured nano-negative ion powder is prepared by mixing tourmaline nanoparticles with tetrabutyl titanate and zinc acetate solution, and forming an 8nm thick titanium dioxide-zinc oxide composite coating on the surface through the sol-gel method, resulting in core-shell structured nano-negative ion powder with an average particle size of 120nm.

[0059] Preparation of Zisha pottery: A composite mixture of 65 parts synthetic Zisha clay, 12 parts surface-modified tourmaline powder, 8 parts core-shell structured nano-negative ion powder, 18 parts metakaolin, 9 parts porous quartz sand, 11 parts potassium feldspar, and 3 parts crystal-controllable rare earth composite oxides was fed into a planetary ball mill. Zirconia balls were used as the grinding media (ball-to-material ratio 4:1), with agate balls comprising 15% of the grinding media. The mill was operated at 250 rpm. Grind and mix for 2 hours at 1 minute intervals to obtain a uniform powder.

[0060] Plasticizing treatment involves adding 28% deionized water and 0.5% sodium carboxymethyl cellulose by weight to the powder. The powder is then kneaded twice using a vacuum kneader at a vacuum of -0.08 MPa to obtain a plastic blank.

[0061] Gradual aging involves placing the billets in a variable-temperature aging chamber, aging them first at 25°C and 75% humidity for 15 hours, and then raising the temperature to 35°C and 65% humidity for another 18 hours.

[0062] Microwave-assisted drying involves placing the shaped ceramic blanks into a microwave drying oven and drying them at 55°C for 5 hours at a power of 400W, followed by heating to 75°C for 7 hours to reduce the moisture content of the ceramic blanks to 6%.

[0063] Segmented firing: The dried clay blanks are placed in the kiln and fired at 4°C. Heat to 600°C at a rate of 6 minutes, hold for 1 hour; continue heating at 6°C. Heating to 1000℃ at a rate of 0.8 m / min, and introducing a protective atmosphere containing 8% oxygen (introduction rate 0.8 m / min). 3 h, the pressure inside the kiln is maintained at 15Pa positive pressure); finally, the temperature is increased to 1200℃ at a rate of 9℃ / min, held for 3.5 hours, and then cooled to room temperature with the furnace.

[0064] Comparative Example 1

[0065] Raw material preparation: Natural purple clay is used, ground to a particle size of ≤50μm with a proportion of 75%, and its chemical composition is SiO2 58%, Al2O3 19%, Fe2O3 11%; unmodified tourmaline powder and ordinary negative ion powder are used directly without surface treatment.

[0066] Preparation of Zisha pottery: 65 parts of natural Zisha clay, 12 parts of unmodified tourmaline powder, 8 parts of ordinary negative ion powder, 18 parts of metakaolin, 9 parts of porous quartz sand, 11 parts of potassium feldspar, and 3 parts of crystallization-controllable rare earth composite oxides were mixed in an ordinary ball mill. 28% deionized water and 0.5% sodium carboxymethyl cellulose were added, and the mixture was kneaded under a vacuum of -0.08 MPa. The mixture was aged for 24 hours at a single temperature of 25℃ and 75% humidity, dried with ordinary hot air, and then fired at a conventional heating rate (without segmented temperature control or atmosphere control). The maximum firing temperature was 1200℃, and the mixture was held at that temperature for 3.5 hours before cooling in the kiln.

[0067] The performance comparison between Example 1 and Comparative Example 1 is shown in Table 1 below.

[0068] Table 1 Performance test data of Example 1 and Comparative Example 1

[0069]

[0070] Therefore, this invention employs the aforementioned method for preparing a purple clay pottery material capable of releasing negative oxygen ions. Through a synthetic purple clay preparation process, using common clay minerals such as montmorillonite, kaolin, and illite as base materials, and compounding them with quartz sand, hematite powder, and alumina powder, a three-step process of grinding, calcination, and sieving is used to obtain synthetic purple clay with strictly controllable chemical composition (SiO2 62%, Al2O3 20%, Fe2O3 9.5%) and particle size distribution (≤50μm ≥80%). This eliminates the regional dependence and compositional fluctuations of natural clay, reducing the sintering shrinkage rate of the green body from 15.2% in traditional processes to below 11.5%, and increasing the density of the finished product by 10%-15%, providing a uniform matrix for the stable dispersion of functional components.

[0071] Surface-modified tourmaline powder is treated with silane coupling agent KH-550, with a surface grafting rate of 5%, which significantly improves its compatibility with the purple clay matrix and increases its dispersibility by more than 30%, thus avoiding functional failure caused by agglomeration.

[0072] The core-shell structured nano-negative ion powder uses tourmaline nanoparticles as the core, coated with a 5-10nm thick titanium dioxide-zinc oxide composite coating. The average particle size of the core and shell particles is 80-150nm. During sintering, a stable core-shell interface structure is formed, improving high-temperature resistance (coating peeling rate <5%) and enabling an initial oxygen negative ion release of ≥2000 ions. cm 3 •s, 24-hour continuous release ≥800 cells / cm 3 •s, which is about 50% better than the traditional solution.

[0073] Gradient aging and microwave-assisted drying: Variable temperature aging promotes full hydration of clay minerals and decomposition of organic matter, increasing the plasticity of the green body by 20%; microwave drying provides uniform heating to avoid cracking, and the moisture content is controlled with an accuracy of ±2%, providing a stable green body for subsequent molding.

[0074] Segmented firing and atmosphere control:

[0075] 600℃ heat treatment removes organic matter and prevents residual carbides from affecting the crystal form;

[0076] A protective atmosphere of 5%-10% oxygen is introduced at 1000℃ to control rare earth composite oxides (Ce). 0.8 La 0.2 O 1.9 It retains the fluorite-type crystal structure, with a specific surface area of ​​20-35 m². 2 g, promotes electron transport and negative ion generation;

[0077] Precise temperature control in the high-temperature range (1180-1220℃) enables the porous quartz sand to form an interlocking structure with the matrix, increasing the product's compressive strength by more than 20%, while also achieving continuous and stable negative ion release.

[0078] The controllable iron element (Fe2O3 8%-12%) in the synthetic purple clay forms a "conductive-catalytic" network with rare earth composite oxides and core-shell structure negative ion powder. Under humid conditions (25℃, RH60%), it accelerates the electrolysis of water molecules, which improves the negative ion release efficiency compared to the solution of simply adding mineral powder. At the same time, the nano-silver loaded on porous quartz sand endows the material with antibacterial function, achieving a multi-performance breakthrough of "air purification + structural reinforcement + antibacterial".

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing purple clay pottery capable of releasing negative oxygen ions, characterized in that, Includes the following steps: S1. Raw material pretreatment: Tourmaline powder and silane coupling agent KH-550 are mixed at a mass ratio of 10:1-15:1, ultrasonically treated at 60-80℃ for 30-50 minutes, and dried to obtain surface-modified tourmaline powder; nano-negative ion powder is mixed with tetrabutyl titanate and zinc acetate solution, and a 5-10nm thick titanium dioxide-zinc oxide composite coating is formed on its surface by sol-gel method to obtain core-shell structured nano-negative ion powder; synthetic purple clay is prepared. S2, Compound Mixture: 55-75 parts of synthetic purple clay, 8-18 parts of surface-modified tourmaline powder, 5-12 parts of core-shell structured nano-negative ion powder, 12-22 parts of metakaolin, 6-12 parts of porous quartz sand, 8-14 parts of potassium feldspar, and 2-4 parts of crystallizable rare earth composite oxides are fed into a planetary ball mill, with zirconia balls as the grinding media, and a ball-to-material ratio of 3:1-5:

1. The mixture is ground and mixed at 200-300 rpm for 1.5-2.5 hours to obtain a uniform powder. The core-shell structured nano-negative ion powder has an average particle size of 80-150 nm. The crystal-controllable rare earth composite oxide is Ce with a fluorite-type crystal structure. 0.8 La 0.2 O 1.9 Its specific surface area is 20-35 m². 2 / g; The porous quartz sand has a pore size distribution of 1-5μm and a porosity of 20%-30%, and its surface is loaded with nano-silver particles accounting for 1%-3% of the weight of the quartz sand. S3. Plasticizing treatment: Add 25%-30% deionized water by weight of the powder to the powder, and add 0.3%-0.8% sodium carboxymethyl cellulose by weight of the powder as a plasticizer. Use a vacuum ply mill to ply the powder 2-3 times under a vacuum of -0.08MPa to obtain a plastic blank. S4. Gradient aging: Place the billet in a variable temperature aging chamber and age it for 12-18 hours at 25℃ and 75% humidity, then raise the temperature to 35℃ and 65% humidity and continue aging for 12-24 hours. S5. Microwave-assisted drying: Place the shaped ceramic blanks into a microwave drying oven and dry them in stages at a power of 300-500W. Dry them at 50-60℃ for 4-6 hours, and then raise the temperature to 70-80℃ for 6-8 hours to reduce the moisture content of the ceramic blanks to 5%-8%. S6. Segmented firing: The dried ceramic blanks are placed in the kiln and heated to 600℃ at a rate of 3-5℃ / min, and held for 1 hour to remove organic matter; the temperature is then increased to 1000℃ at a rate of 5-8℃ / min, and a protective atmosphere containing 5%-10% oxygen is introduced; finally, the temperature is increased to 1180-1220℃ at a rate of 8-10℃ / min, held for 3-4 hours, and then cooled to room temperature in the kiln. The preparation steps of the synthetic purple clay described in step S1 specifically include: S01. Preparation of basic raw materials for purple clay: Weigh 40-60 parts by weight of montmorillonite, 20-30 parts by weight of kaolinite, and 10-20 parts by weight of illite as the main minerals, and 10-15 parts by weight of quartz sand, 5-10 parts by weight of hematite powder, and 3-8 parts by weight of alumina powder as auxiliary components. Put them into a planetary ball mill and grind them for 3-5 hours at 300-400 rpm using deionized water as the medium to obtain a mixed slurry with an average particle size ≤10μm. S02, High-temperature calcination crystallization treatment: The mixed slurry is dried at 105℃ to a moisture content of ≤5%, crushed and placed in a sagger, and then placed in a high-temperature kiln. The temperature is raised to 1000-1200℃ at a rate of 10-15℃ / min and held for 2-3 hours to allow montmorillonite to delaminate, illite to decompose and promote the formation of mullite crystal nuclei. Nitrogen gas with a flow rate of 5-10L / min is introduced during the calcination process to protect against excessive oxidation of iron. S03. Fine screening and grading: After the calcined product is coarsely crushed by a jaw crusher, it is passed through a 200-mesh sieve to remove coarse particles, and then classified by an air classifier to make the proportion of particles with a diameter ≤50μm ≥80%, thus obtaining synthetic purple clay.

2. The method for preparing a purple clay pottery capable of releasing negative oxygen ions according to claim 1, characterized in that, The grinding media of the planetary ball mill described in step S2 contains 10%-20% agate balls with a diameter of 1-3 mm.

3. The method for preparing a purple clay pottery capable of releasing negative oxygen ions according to claim 1, characterized in that, The humidity control accuracy of the variable temperature aging chamber in step S4 is ±5%, and the temperature control accuracy is ±2℃.

4. The method for preparing a purple clay pottery capable of releasing negative oxygen ions according to claim 1, characterized in that, The rate at which the protective atmosphere is introduced in step S6 is 0.5-1.0 m. 3 / h, the pressure inside the kiln is maintained at 10-20Pa positive pressure.

5. A purple clay pottery that can release oxygen negative ions, prepared by any one of claims 1-4.

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